Pentafluorosulfanylbenzoic acids are compounds useful as intermediate materials for drugs and agricultural chemicals (see, for example, PTLs 1 and 2). One known method for producing a pentafluorosulfanylbenzoic acid involves a step of reducing 4-nitro(pentafluorosulfanylbenzene) into 4-amino(pentafluorosulfanylbenzene), a step of reacting the compound with butyl nitrite to form a diazo compound and then brominating the compound with copper(II) bromide to form 4-bromo(pentafluorosulfanylbenzene), a step of lithiating the compound with t-butyllithium and then formylating the compound to form 4-(pentafluorosulfanyl)benzaldehyde, and a step of oxidizing the compound with silver oxide to form 4-(pentafluorosulfanyl)benzoic acid (NPL 1).
Another known method for producing a pentafluorosulfanylbenzoic acid involves reacting 4-bromo(pentafluorosulfanylbenzene) with metallic magnesium and methyl iodide to prepare a Grignard reagent and then reacting the reagent with carbon dioxide to form 4-(pentafluorosulfanyl)benzoic acid (NPL 2).
Still another known method involves synthesis of 4-iodo(pentafluorosulfanylbenzene) from 4-amino(pentafluorosulfanylbenzene), conversion of the compound with tributylvinyltin in the presence of a palladium catalyst into 4-vinyl(pentafluorosulfanylbenzene), and conversion of the compound with sodium periodate in the presence of a ruthenium catalyst into 4-(pentafluorosulfanyl)benzoic acid (PTL 1).